In recent years, there continues to be dramatic density increases in integrated circuit technology for semiconductor chips. For example, the minimum feature size of lithography, such as the size of MOSFETs, has been reduced to one micrometer and below. In the fabrication of precision capacitors in conjunction with FET devices on the same chip at these reduced dimensions, it is increasingly difficult to maintain manufacturing parameters such that precise outputs from these devices are still available.
The integrated circuits have been applied in various electronic devices, such as cellular phones, PDAs, computers, and/or other electronic devices. Conventionally, an external power received by the electronic devices is different than that for operating the integrated circuits of the electronic devices. For example, a laptop computer conventionally receives a 20-V power from batteries and integrated circuits of the computer functions under 3 V or 5 V. To convert the supplied power to the internal operating voltage, DC-to-DC converters have been widely applied.